This document defines nutrition and describes the steps and roles in the nutrition process. It explains that nutrition involves ingesting, digesting, absorbing, assimilating, and egesting foods that provide nutrients to support the body's life functions. Nutrients include carbohydrates, proteins, fats, fiber, water, vitamins, and minerals which come from various food sources. A balanced diet containing adequate amounts of all necessary nutrients is important for health, while deficiency or excess of certain nutrients can lead to diseases.